Familial hypercholesterolemia (FH) is caused by a pathogenic mutation in the low-density lipoprotein (LDL) receptor (LDLR) or its associated genes, including apolipoprotein B (APOB), proprotein convertase subtilisin/kexin type 9 (PCSK9), and LDLR adaptor protein 1 (LDLRAP1).1 The gene discussed is APOB; the disease is familial hypercholesterolemia.